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1.
The sex ratio produced by an individual may be a consequence of relative frequencies of genotypes amongst offspring, or may result directly from parental (maternal) control. We analyse the evolutionarily stable sex ratio for a hypothetical organism in which both forms of sex ratio expression can occur. We prove that the point of expression of sex ratio does not affect the evolutionarily stable sex ratio for diploid hosts in populations infected with cytoplasmically inherited sex ratio distorters.  相似文献   

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The influence of multiple oral doses of cholestyramine on the single dose pharmacokinetics of meloxicam has been studied in 12 healthy male volunteers. Each subject received on two occasions a single IV injection of meloxicam 30 mg. The cholestyramine group received the material suspended in water 3 times a day. Compared to controls, cholestyramine accelerated the elimination of meloxicam. The mean terminal phase elimination half-life was reduced from 19.5 h to 12.7 h due to an increase in clearance of the drug (0.426 vs 0.636 l.h-1). Also, as a consequence of increased clearance in the presence of cholestyramine, the mean residence time of the drug in the body was significantly decreased (39%) P < 0.01. However, the volume of distribution for meloxicam was largely unaffected by cholestyramine which suggests that meloxicam undergoes gut recirculation. These changes are of the same magnitude as those previously reported for the structurally related piroxicam and are much smaller than those observed for tenoxicam.  相似文献   

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The host immune response to human papillomaviruses (HPVs) is believed to be an important determinant of progression of HPV-associated cervical neoplasia. Human leukocyte antigens (HLAs) are important in the presentation of foreign antigens to the immune system. Previous studies have suggested a possible association between HLA and cervical neoplasia, but the specific alleles found to be associated with disease have varied between studies. To further evaluate this issue, we conducted a nested case-control study within a 24,000-woman cohort study in the United States. A total of 711 women were selected for the study: 141 women diagnosed with high-grade squamous intraepithelial lesions (HSILs) of the cervix; 202 women diagnosed with low-grade SILs (LSILs); 166 women with no history of cervical neoplasia, but evidence of HPV-16 infection; and 202 women with no history of cervical abnormalities and who were HPV negative during follow-up as part of our cohort. Cervicovaginal lavage samples collected from participants were used for HPV testing by L1 consensus primer PCR and the Hybrid Capture tube test methods. DNA extracted from these same lavage samples were used for PCR-based HLA genotyping. Our results suggest a positive association between HLA B7 and HLA DQB1*0302 and disease. A negative association with disease was observed for HLA DRB1*1501-DQB1*0602 and DRB1*13. Associations were strongest when analyses were restricted to HPV-16-positive cases as follows. Compared with women who were cytologically normal and HPV negative, HLA B7 was associated with a 1.5-fold increased risk of HPV/LSIL [95% confidence interval (CI) = 0.95-2.5] and a 2.5-fold increased risk of HSIL (95% CI = 1.2-5.1). HLA DQB1*0302 was associated with a 1.5-fold increased risk of HPV/LSIL (95% CI = 0.94-2.4) and a 1.7-fold increased risk of HSIL (95% CI = 0.84-3.5). HLA DRB1*1501-DQB1*0602 was associated with a decreased risk of HSIL [relative risk (RR) = 0.21; 95% CI = 0.07-0.62]. HLA DRB1*13 was associated with a decreased risk of HPV/LSIL (RR = 0.78; 95% CI = 0.51-1.2) and HSIL (RR = 0.63; 95% CI = 0.30-1.3). Individuals who were either homozygous for DQB1*0302 or carriers of both B7 and DQB1*0302 were found to be at highest risk of disease (RR = 4.5, 95% CI = 1.5-14 for HPV/LSIL; and RR = 9.0, 95% CI = 2.4-34 for HSIL). No synergistic effect was observed for the alleles found to be associated with reduced risk of cervical neoplasia. Our findings support previous studies that have found HLA B7 and DQB1*0302 to be positively associated with cervical neoplasia and are consistent with those that have suggested that DRB1*13 is negatively associated with disease, but do not confirm previous assertions that DRB1*1501-DQB1*0602 increases the risk of cervical disease.  相似文献   

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OBJECTIVE: To evaluate the autonomic response in preterm neonates born after an at-risk pregnancy. METHODOLOGY: Twenty-one preterm neonates (gestational age; GA) 29-37 weeks; bodyweight (BW): 720-2113 g; postnatal age: 2-126 days), born after at-risk pregnancies (stressed (STR) group), were compared to 30 preterm neonates (GA: 26-36 weeks; BW: 813-2380 g: postnatal age: 2-86 days) without any intrauterine risk factor (C group). A 10 s pain stimulus was given on the forefoot and heart rate, respiratory rate and blood pressure were measured at 15 and 30 s, at 1, 2, 3, 4 and 5 min. After 10 s ocular compression six cardiac variables were recorded. RESULTS: After the pain stimulus the STR-group had a significant increase of heart rate at 15 s and an increase of diastolic blood pressure at 30 s. In the C group a significant increase of heart rate at 15 s was recorded. For the respiratory rate both groups showed an initial depression (significant at 15 s in the C group) followed by an increase. The time to react to the ocular compression was significantly shorter in the STR-group than in the C-group and thus more parasympathetic. CONCLUSIONS: We hypothesize that the different sympathetic and parasympathetic reaction patterns of the vital parameters to triggers in the STR-group are due to chronic stress, pointing to an altered maturation of the two components of the autonomic nervous system after chronic intrauterine stress (CIUSTR).  相似文献   

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A 13-year-old boy presented with acute loss of vision in his right eye of 2 weeks' duration. He had a high fever and was ill for several days, then improved but suffered recurrent episodes of sweating and a high fever. Ophthalmoscopy of the right eye showed optic disk edema, mild vitreous cells, and minimal exudates in the macula. Bartonella henselae titers were positive. A diagnosis of optic disk edema with a macular star secondary to cat-scratch disease was made. The patient was treated with doxycycline and made a dramatic improvement to visual acuity of 20/30 with a minimal residual relative central scotoma. The optic disk edema and macular star resolved, and the patient was left with mild optic atrophy in the right eye.  相似文献   

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Helminth-free donor pigs were inoculated with infective larvae of Oesophagostomum dentatum. Five weeks later, the donor pigs were killed to recover the adult worms. By nonsurgical rectal transplantation, 6 groups of helminth-free recipient pigs were then given different female-to-male ratios (FMR) of O. dentatum worms (10% females [F], 50% F, 90% F) at either high (300 worms) or low (30 worms) doses. Fecal egg excretions were measured once weekly following transplantation until the pigs were killed 4 wk posttransplantation to assess the worm burdens and their location. There was a strong and significant correlation between numbers of male and female worms located in the different sections of the large intestine, suggesting that the worm sex as well as physiological factors in the pig intestine may govern the location of the worms. There were no significant differences in fecal egg counts or female worm fecundity between any of the groups. However at the low dose level, the female worm fecundity was markedly lower in the L10% F group than in the 2 other groups, thus suggesting for low worm densities an upper threshold for the FMR above which O. dentatum females produce fewer eggs.  相似文献   

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The present paper investigates the effects of two anaesthetic drugs (pentobarbital and etomidate) on both short-term variabilities of systolic blood pressure (SBP) and heart rate (HR) using fast Fourier transformation and catecholamine plasma levels. HR and BP were continuously recorded through an arterial catheter and blood samples were taken from the jugular vein. Spectral analysis was performed first in the conscious state and six minutes after induction of anaesthesia on a series of 256 consecutive BP and HR values (delta t: 2 Hz). The area under the curve (AUC) was determined in the low-frequency component of the SBP (LF: 40-150 mHz), in the high-frequency band of HR (HF: respiratory frequency +/- 50 mHz) and in the total frequency spectra. Results were normalized by calculation of the ratio between AUC of LF and HF and the total AUC of the corresponding spectrum (TS). Etomidate (2 mg/kg i.v.) induced a significant increase in TS and LF without changing the LF/TS ratio or the HR variability when compared with the awake period. Catecholamine plasma levels did not change. In contrast, pentobarbital (30 mg/kg i.v.) decreased the values of LF, HF, LF/TS and HF/TS and catecholamine plasma levels. These results suggest that pentobarbital decreases the activity of the two components of the autonomic nervous system whereas etomidate induces only minimal changes.  相似文献   

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目的:观察急性根尖周炎常规开髓引流后进行负压引流以减轻临床症状的疗效.方法:将本院收治的急性根尖周炎的患者142例,随机分为实验组(72颗患牙,负压吸引引流)和对照组(70颗患牙,常规开髓引流).比较两组患者临床症状的缓解情况以及根管内白细胞介素1β(IL-1β)、前列腺素E2(PGE2)及C反应蛋白(CRP)水平的变化.结果:两组数字化疼痛评判法(VAS)差值比较差异具有统计学意义(P<0.05).实验组IL-1β、PGE2和CRP变化的差值大于对照组(P<0.05),实验组的治疗有效率高于对照组(P<0.05).结论:应用负压引流等一系列处置能有效缓解急性根尖周炎的症状,愈后良好.  相似文献   

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Fibroblasts have an important structural role in the spleen, as they provide a scaffold of extracellular matrix in which cells of the immune system reside. Aside from their vague recognition as "stromal" or "reticular" components of the spleen, these cells have not been characterized. In this study, normal fibroblast lines from mouse [B6D2(F1)] spleen were established. The fibroblast phenotype of these lines was confirmed by their morphology, expression of vimentin, as well as their lack of epithelial and endothelial cell markers, their failure to display the hematopoietic marker CD45, and their inability to phagocytize. Interestingly, 50-65% of the splenic fibroblasts expressed the Thy-1 antigen, while a subpopulation of Thy-1-negative fibroblasts existed. FACS on the basis of Thy-1, as well as limiting dilution cloning, yielded stable lines and clones of Thy-1+ and Thy-1- splenic fibroblasts. Phenotypic characterization revealed that both subsets synthesized collagen and expressed class I MHC, ICAM-1, VCAM-1, and CD44 constitutively. However, intriguing differences existed between the fibroblast subpopulations. Thy-1+ splenic fibroblasts produced significantly greater levels of IL-6 than did their Thy-1- counterparts. After treatment with IFN-gamma (150 U/ml, 72 hr), Thy-1-, but not Thy-1+, splenic fibroblasts expressed class II MHC and presented antigen to an I-A(b)-restricted T cell line. This suggests that the Thy-1- fibroblasts may present antigen to T lymphocytes in vivo under inflammatory conditions. Thus, splenic fibroblasts are a heterogeneous and dynamic cell type poised in an immunologically relevant location to interact with bone marrow-derived cells under normal and fibrotic conditions.  相似文献   

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The aim of the present experiment was to assess the effect of the administration of the NSAID flurbiprofen (Froben) on tissue healing after periodontal surgery. Sites from patients with the same treatment modality (modified Widman flap) but receiving a placebo drug and sites within each patient not exposed to surgery served as controls. Nineteen patients suffering from moderate to severe periodontal disease were recruited and they signed informed consent forms. These patients required periodontal surgery as assessed at the periodontal re-evaluation. The sites chosen for the study were all diagnosed with PPD > or = 5 mm and were bleeding on probing. During the healing phase 10 patients received 50 mg Froben 3 times per day for 30 d whereas 9 patients received a placebo drug. Two sites with PPD > or = 5 mm after initial therapy and bleeding on probing served as surgical sites, whereas 2 similar sites were not exposed to surgery. The study design was set up double-blind. The radiographic examination consisted of 2-4 standardized vertical bitewings obtained at the periodontal re-evaluation (BL) at 1, 3 and 6 months post-surgically for digital subtraction and computer assisted densitometric image analysis (CADIA). The regions of interest analysed were mesial or distal crestal sites. Minimal remodelling activity was observed radiographically after periodontal surgery in both patient groups. There were no statistically significant differences between the four groups of sites regarding the mean changes in density when analysing the pairs of radiographs 0-1, 0-3, 0-6 months. A frequency analysis was performed to list the number of sites with different ranges of density change. No differences in the distributions of the numbers of sites were observed when comparing the 4 site groups (Kolmogorov-Smirnov, p > 0.05). A significant reduction of the probing pocket depth and a significant amount of clinical attachment gain was noted at the surgically treated sites irrespective of whether the patients had used flurbiprofen or placebo. Whereas the pathways leading to bone resorption in periodontally diseased sites have been shown, in other studies, to be influenced by NSAID, the results of the present study could not justify general administration of Froben for the purpose of reduction of bone resorption after periodontal surgical procedures in patients with adult periodontitis.  相似文献   

14.
The dynamics of the leukocyte index of intoxication (LII) and the blood-cell index (BCI) was studied in 2756 patients with erysipelas. Both indexes, raised at the height of the disease, are lowering under the therapy influence. At the purulent-inflammatory complications beginning the LII and BCI level remains high or raises 2-3 days before occurrence of clinical signs of complication. The application of above-mentioned indexes for prognostication and diagnosis is possible.  相似文献   

15.
将炼铁厂高炉喷吹所使用的无烟煤、烟煤、褐煤以不同配比制取混合煤样,对其着火点、可磨性以及燃烧性能进行研究.实验结果表明:每加入5%褐煤后会降低混合煤样的着火点4℃左右;在烟煤、无烟煤混合的煤样中加入15%褐煤会使可磨性指数加权值减少7,但实际值降低了 14.加入褐煤后,2种配煤方案中煤粉燃烧性能的主要影响为降低着火温度...  相似文献   

16.
The hypothesis that teeth act as reservoirs of micro-organisms for the colonization of oral implants has recently been stated several times. The present study aimed at examining, in partially edentulous patients with severe periodontitis, whether pockets around teeth and implants harbored a comparable micro-flora. In 6 patients (3 with refractory periodontitis and 3 with advanced chronic adult periodontitis), plaque samples were taken from a deep and shallow pocket around both teeth and implants for differential phase contrast microscopy and DNA probe analysis. The results showed important differences in the sub-gingival flora between the 2 disease groups, as well as between deep and shallow pockets, around both implants and teeth. On the other hand, when pockets around teeth and implants with equal depths were compared a striking similarity was observed in the microbial composition. These observations confirm the hypothesis that pockets around teeth act as a reservoir and highlight the importance of periodontal health when oral implants are planned.  相似文献   

17.
Analysis of the function of the nervous system, based on clinical, neurological, and psychological studies in 78 patients with generalized periodontitis, revealed central regulation disorders without signs of organic lesions of the brain in 76% patients. The authors claim that stress and a high level of personal anxiety may be responsible for the development of these disorders, which was confirmed by the results of psychological testing.  相似文献   

18.
OBJECTIVE: Marginal leakage of amalgam restorations may lead to secondary caries and pulpal damage. The purpose of this study was to determine the effect various cavity liners might have on microleakage. METHOD AND MATERIALS: Mesio-occlusodistal amalgam restorations with margins on enamel and dentin were treated with different liner materials (an adhesive system, a topical fluoride gel, a cavity varnish, and a glass-ionomer cement) in vitro. Following restoration, the teeth were submitted to thermocycling in a stained solution and sectioned to allow assessment of microleakage. RESULTS: On enamel, the control group (no liner) and the glass-ionomer-lined group had equivalent leakage scores and were superior to every other group. On dentin, only the glass-ionomer specimens had superior performance. The cavity varnish and fluoride-lined specimens exhibited the highest leakage scores. CONCLUSION: The use of liners does not reduce microleakage on amalgam restorations when the cavity margins remain on enamel. On dentin margins, a glass-ionomer liner can reduce microleakage.  相似文献   

19.
Ketoprofen is a non-steroidal antiinflammatory drug (NSAID) which provides effective analgesia in situations of pain provoked by tissue inflammation. However, the location of its analgesic effects, (peripheral tissues versus central nervous system), have not been clearly identified and separated. In the present study the effectiveness of ketoprofen was examined in two different types of experiments: (i) Open field behavioural tests in conscious rats, and (ii) spinal cord nociceptive reflexes (single motor units) activated by electrical and thermal stimulation in chloralose anaesthetised rats. The experiments were performed in rats with carrageenan-induced inflammation of one hindpaw, or of one knee joint. The administration of ketoprofen significantly inhibited the reduction of exploratory movements caused by inflammation in open field experiments. Ketoprofen was also effective in depressing reflex activity evoked by electrical and noxious thermal stimulation of the skin, either in inflamed tissue or in normal tissue of monoarthritic animals. It was also effective in the reduction of reflex wind-up; a phenomenon in which the activity of spinal cord neurones increases progressively with high frequency electrical stimulation. We therefore conclude that ketoprofen has central as well as peripheral analgesic activity.  相似文献   

20.
A stepwise approach to determine attachment level changes was utilized to assess the nature of progression of periodontal disease. Following initial screening, 51 subjects with established periodontitis were monitored quarterly for 9 more months. Probing depth (PD) and relative attachment level (RAL) were recorded using an automated, pressure sensitive probe system. To establish intra-examiner error, repeated measurements were performed for all sites at the final visit. An overall standard deviation (SD) for RAL repeated measurements was initially calculated (0.76 mm) using all 6,935 double measurements. Sites were sorted by factors which contribute to the error of attachment level measurements; i.e., pocket depth (shallow, moderate, deep), tooth type (molar, non-molar) and location (buccal, lingual). Data were sorted by the above 12 groups, and SD for repeated measurements was calculated separately for them. The ratio between these SD and the overall SD served as the corrective factor. Each patient's initial threshold (2 SD) was multiplied by these corrective factors thus resulting in 12 thresholds for each subject. Next, linear, exponential and logarithmic regression models were tested for each site, and the regression model showing the highest R value was chosen for that site. AL changes were tested against the patient's threshold for that site. Sites with attachment loss exceeding the threshold were deemed active. Five hundred eighty-one sites (8.3%) exhibited attachment loss exceeding the various thresholds. Of these, linear progression occurred in 195, logarithmic in 224, and exponential in 162 sites. Individual patient's attachment loss ranged from 0.6 to 19.4% of all sites.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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